<p>(A) Polarized Caco-2 monolayers were infected with KC12 and EPEC strains for 6 h, fixed, and stained to visualize bacteria, F-actin, and DNA. Scale circles, 100, 500, 1000 μm<sup>2</sup>. (B) Macrocolony sizes >100 μm<sup>2</sup> from experiments described in (A) were measured and binned into size groups. Each bar represents the mean number of macrocolonies (+/- SE) from 3 experiments, spanning 225–275 fields of view (FOV) and 4658–8434 colonies. All p-value significance is in reference to the 100–250 μm<sup>2</sup> bins. *p<0.05, **p<0.01 (ANOVA, Tukey post-hoc tests). (C) Data collected in (B) were reorganized to compare the strains within each category. Bars represent the mean (+/- SD) for 3 experiments, of the % of colonies falling into each bin. Asterisks are in reference to KC12+EspF<sub>U</sub>. *p<0.05, **p<0.01 (ANOVA, Tukey post-hoc tests). (D) Macrocolony sizes measured from part (B) were averaged. Each bar represents the mean (+/- SD) from 3 experiments. All p-values are in reference to KC12+EspF<sub>U</sub>. (E) Experiments were performed as in (A), but for 7 h. Each bar represents the mean (+/- SE) of the % of monolayer area infected for 58–60 FOVs. (F) The number of infected cells per macrocolony was calculated. Each bar represents the mean (+/- SE) calculated from 238–497 macrocolonies, taken from 17–19 representative fields of view from the images quantified in (E). *p<0.05, **p<0.01 (ANOVA, Tukey post-hoc tests).</p
